Molloy M, Bower R H, Hasselgren P O, Dalton B J
Surgical Service, Veterans Affairs Medical Center, and the Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
J Gastrointest Surg. 1999 Mar-Apr;3(2):185-8. doi: 10.1016/s1091-255x(99)80031-6.
The ability to perform intraoperative cholangiography during laparoscopic cholecystectomy is an essential skill for the laparoscopic biliary surgeon. The volume of experience required to be able to consistently obtain a cholangiogram during laparoscopic cholecystectomy has not been determined. Cumulative sum analysis is a statistical technique which generates a graphical display that identifies periods of performance that fall below a predetermined standard for a given task. The cumulative sum (S(n)) for a series of observations is defined as: S(n)= summation operatorX(I) - X(o), where X(I) = 0 for a success, X(I) = 1 for a failure, and X(o) is the acceptable failure rate for the process under study. This function is plotted against the number of observations to create a curve. When the curve has a positive slope, the acceptable failure rate is being exceeded. When it reaches a plateau, the observed failure rate is equal to the acceptable failure rate. When the curve has a negative slope, the observed failure rate is lower than the acceptable failure rate. We performed a cumulative sum analysis of the first 97 intraoperative cholangiograms attempted during lap-aroscopic cholecystectomy at our institution. The results demonstrated that 46 cases were required to reach a level of proficiency where a cholangiogram could be obtained in 95% of attempts. Success rates of 85% and 90% were achieved at 16 and 25 cases, respectively. This form of analysis is a useful tool for estimating the number of attempts required to achieve a desired success rate when learning new procedures.
在腹腔镜胆囊切除术中进行术中胆管造影的能力是腹腔镜胆道外科医生的一项基本技能。在腹腔镜胆囊切除术中始终能够获得胆管造影所需的经验量尚未确定。累积和分析是一种统计技术，它生成一种图形显示，可识别给定任务中低于预定标准的表现期。一系列观察值的累积和（S(n)）定义为：S(n)=求和运算符X(I)-X(o)，其中成功时X(I)=0，失败时X(I)=1，X(o)是所研究过程的可接受失败率。该函数与观察次数作图以创建一条曲线。当曲线具有正斜率时，超过了可接受失败率。当它达到平稳期时，观察到的失败率等于可接受失败率。当曲线具有负斜率时，观察到的失败率低于可接受失败率。我们对本机构在腹腔镜胆囊切除术中尝试的前97例术中胆管造影进行了累积和分析。结果表明，需要46例才能达到熟练水平，即95%的尝试中能够获得胆管造影。在16例和25例时分别达到了85%和90%的成功率。这种分析形式是学习新手术时估计达到期望成功率所需尝试次数的有用工具。
